1970 340 Duster Flexplate Suggestions

[FJRdoc]

I will soon be ready to bolt up my 727 to my 340. My tranny has been rebuilt and I am going to add a 2400 stall converter. The rebuilt stock engine is 312 hp and 324 torque. My original flex plate looks good but I've decided to get a new one since this is the time to change it out.
I doubt that I'm going to thrash this car after it's back on the street. I do intend to have fun with it. Should I just go with an original style flex plate or do you suggest an upgrade?

 

[Locomotion]

I would suggest an upgrade. Cheap insurance. OEM may last, but I've seen too many, including the solid-eared versions, crack under hard use, usually racing.

If going aftermarket, make sure you have the proper bolt pattern and size - depending on your converter. B&M covers all the bases.

 

[FJRdoc]

I'll have to measure my torque converter bolt spacing later tonight. Since my engine a 1970, I will need to get a flexplate for an internally balanced engine......right?

 

[Locomotion]

I'll have to measure my torque converter bolt spacing later tonight. Since my engine a 1970, I will need to get a flexplate for an internally balanced engine......right?

Yes. I'm thinking that the OEM bolts will be 5/16". Aftermarket performance converters often have 7/16" bolts and small radius pattern. (If that's the correct terminology.) I don't recall if the OEM converter bolt pattern was on the smaller or larger radius.